The present invention relates generally to nasal ventilation systems, and more particularly, to a valved nasal ventilation interface for supporting respiration.
Nasal ventilators generally consist of tubes and other means for delivering gases adapted for use with the nasal or oral passage of a patient. Typically, a nasal ventilation system comprises a gas source and a mechanical ventilator such as a continuous positive airway pressure system (CPAP), bi-level positive airway pressure system (BIPAP), or intermittent (non-continuous) positive pressure (IPPB). The gas is often room air or oxygen-enriched air, but can be a mixture of other gases.
The gas is transported by a thin flexible tube made of an inert material. The tube terminates in an opening which can be inserted into the patient""s nostrils. Typically, a pair of smaller nasal insert tubes protrude from the tube or the tube splits at a Y-junction into two smaller tubes, cach smaller nasal insert tube carrying gas to one nostril, thereby increasing the fraction of inspired oxygen.
Conventional nasal tube systems do not provide a positive seal between the nasal insert tubes and the nostrils. Most nasal ventilation systems therefore include a mask that fits over the nose and is intended to provide a space of oxygen-enriched air for inhalation into the lungs for respiration. Such systems frequently suffer from air leaking out around the mask, creating an inability to assure ventilation in many patients.
For example, conventional nasal ventilation systems use head gear and/or straps to bind the mask in place, but in order to minimize the leakage of the air the straps must be sufficiently tight. The mask, headgear, and/or straps thereby exert more than a minor pressure on the patient""s face and/or head, resulting in such masks and headgear tending to be rather constraining and uncomfortable.
Additionally, most systems are usually very position dependent, whereby if the mask is moved slightly with respect to the facial contour or with respect to the nose, air leakage occurs. With such systems, the mask can become uncomfortable when not in position, thus requiring the patient to remain rather still in order to alleviate the discomfort and to maintain oxygen inspiration. As a result many patients lose interest in using the nasal mask.
Also, some ventilation systems have exhalation valves for the treatment of breathing problems. Various valve systems have been devised but they all function similarly. Typically, the exhalation valve is positioned at the ventilator or in the tubing at least a foot or more from the patient, and the air that is exhaled by the user is trapped in this xe2x80x9cdead spacexe2x80x9d between the patient and the valve. Such ventilation systems with exhale valves are typically bulky and heavy. The patient thus has to have a tidal volume (breath) that is a little larger than otherwise needed to compensate for the deadspace. This larger tidal volume is noticeable by the patient and can be a nuisance while trying to sleep soundly.
Related types of nasal tube systems include low flow oxygen systems which merely provide oxygen concentration. These systems typically provide nasal insert tubes that are loosely inserted into the nasal cavities without a mask. Such systems are low pressure systems for providing oxygen enrichment to the ambient air that the patient breathes, are not ventilators (do not provide positive pressure for forced ventilation/breathing), and could not function as ventilation systems because of the lack of a seal between the cannula interface and the patient, the smaller tubing size, and the low pressure of the system.
Additionally, there are no known portable, wearable devices that completely filter out the allergens that trigger allergic reactions in asthmatics and allergy sufferers. There are only aerosol treatments and other medications that treat the symptoms, that is, the allergic reactions themselves. Furthermore, when a patient presents to an emergency room with severe bronchial constriction in response to allergens, a bronchodilator is typically administered to dilate the tracheal airways and bronchioles so that gas exchange is maintained in the alveoli of the lungs. However, if bronchial dilation is successful then allergens are also allowed to be breathed deeper into the bronchioles. Bronchiole constriction is a bodily reaction to keep any further allergens from reaching the smaller airways. Forced dilation and deeper penetration of allergens often results in an even more violent reaction after the bronchodilator has lost some of its therapeutic effect. This worsened reaction sometimes becomes life-threatening and can cause death, in particular, to a patient with status asthmaticus.
Furthermore, present cloth surgical masks typically worn by doctors, surgeons, and other medical personnel do not filter out many pathogens. Also, they are hot to the wearer and can obstruct the wearer""s view, especially when looking down during a surgical procedure. Dentists are concerned with spray and do not trust the presently available surgical masks.
Accordingly, what is needed but not found in the prior art is a nasal interface apparatus that can be used with a positive pressure ventilation system for supporting respiration, that directs substantially all the air delivered to the nasal interface into the patient""s lungs, that is comfortable and unconstraining to the patient wearer.
Generally described, the present invention provides a nasal ventilation interface comprising a hollow body having at least one and preferably two nasal apertures, at least one and preferably two inhale apertures, at least one and preferably two connectors each capable of being removably attached to at least one of preferably two interface tubes, and at least one and preferably two nasal insert tubes each associated with one of the nasal apertures of the body and capable of being inserted into a nostril of a patient. Each nasal insert tube has an annular sleeve with a contact surface and a diameter that is greater than a diameter of the nasal insert tube so that each annular sleeve contact surface is thereby capable of forming a seal with the nostril. The nasal insert tube may be detachably coupled to the hollow body. There may also be provided a three-way junction capable of being removably connected to a feed tube.
The hollow body may have at least one exhale aperture and at least one valve assembly associated with the exhale aperture that is capable of preventing air from passing through the exhale aperture upon the patient inhaling and allowing air to pass through the exhale aperture upon exhaling. The hollow body may also have at least one filter that retains heat and/or moisture from air passing therethrough upon inhalation and that transfers the heat and/or moisture to the exhalation air that subsequently passes therethrough upon exhalation.
In a first embodiment of the present invention, each valve assembly comprises a valve member pivotally attached to a first inner wall of the and a second valve member pivotally attached to a second inner wall of the body opposite the first inner wall. The first and second valve members overlap and abut each other so that each valve member may pivot in response to the other valve pivoting. In a second embodiment of the present invention, each valve assembly comprises a one-way inhale valve membrane arranged in the body between the nasal aperture and the exhale aperture or disposed within the inhale aperture, and a one-way exhale valve membrane disposed within the exhale aperture. In a third embodiment of the present invention, the body is provided for use without the gas supply, mechanical ventilator, or tubing, valving may or may not be provided, and a filter is provided for screening out dust, allergens, pollen, bacteria, viruses, pathogens, and other air-borne particle matter, so that the invention may be used as a portable nasal filtration device.
Accordingly, it is an object of the present invention to provide a positive pressure closed system providing for full ventilation of a patient with oxygen enrichment capabilities typically provided by low pressure oxygen concentrator and cannula tubing systems.
It is another object of the present invention to provide a nasal ventilation interface having improved patient comfort for use over extended periods.
It is a further object of the present invention to provide a nasal ventilation interface having increased gas delivery efficiency and with minimal or no leakage of gas from the nostrils.
It is still another object of the present invention to provide a nasal ventilation interface having automatic valving for inhaling and exhaling.
It is yet another object of the present invention to provide a nasal ventilation interface with a valve assembly that decreases the amount of deadspace that is rebreathed by the patient.
It is yet a further object of the present invention to provide a nasal ventilation interface that filters the air that is inhaled and/or exhaled for heat, moisture, allergens, pollen, bacteria, viruses, pathogens, and other air-borne particle matter.
These and other objects, features, and advantages of the present invention are discussed or apparent in the following detailed description of the invention, in conjunction with the accompanying drawings and the appended claims.